.45 Colt

The .45 Colt (11.43×33mmR), often called the .45 Long Colt, is a rimmed straight-walled, centerfire handgun cartridge dating to 1872. It was originally a black-powder revolver round developed for the Colt Single Action Army revolver. This cartridge was adopted by the U.S. Army in 1873 and served as an official US military handgun cartridge for 19 years, before being replaced by the .38 Long Colt in 1892. Although there has never been a ".45 Short Colt" cartridge, there was a ".45 Colt Gov" cartridge produced for a short time with a slightly shorter case sharing the same rim diameter as the .45 colt and using a reduced powder charge, not to be confused with the .45 Schofield with a larger rim diameter, which was also in use around the same time as the .45 Colt and able to be used in revolvers chambered in the more powerful Colt round.